Catheter with safety indicator



United States Patent [72] Inventor Daniel M. McWhorter 2,845,930 8/1958 Brown...-. 128/348 Palatine, Illinois 3,211,152 10/1965 Stern 128/351 [211 App]. No. 849,228 3,275,001 9/1966 Rosecrans 128/349 [22] Filed July 14,1969 3,407,817 10/1968 Galleher 128/351 Continuation of S81. N0. 549,021, FOREIGN PATENTS May 10,l970,abandoned patented Dec. 1, 1970 733,890 7/1955 Great Britain 128/349 [73] Assignee The Kendall Company Primary Examiner-Dalton L; Truluck B t M h ett Attorneys-Robert D. Chodera, James 1. Fawcett and T. W. a corporation of Massachusetts Undefhi" [54] INDICATOR ABSTRACT: An improved inflatable retention catheter is described wherein the catheter includes a signal device [52] US. Cl. 128/349 adapted [0 be, activated where i fl i f the retention A611" 25/00 icon is impeded by the walls of the body cavity where the ofSeal'th catheter is being inserted The ignal member is designed to 344, 348-451; l 14 prevent further inflation of the retention balloon as well as indicatin the hysical im ediment to inflation, thereb [56] References Cited minimi ing the danger of pain and trauma caused by inflating UNITED STATES PATENTS the retention balloon when improperly inserted in the body 2,473.742 6/1949 Auzin 128/349 cavity.

' Patented Dec. 1, 1970 Sheet 1 012 ba he/1 Zcrr: ZjanZe/ M /VC Patented Dec. 1, 1970 Sheet 2 012 mm A.

The objects of the invention are preferably attained by I providing an insertion tube with two inflatable portions of thin Some such tubes presently utilized are intended to be retained in body channels by partial inflation of their retention means against the channel walls. Other such tubes presently utilized as, for example, urinary catheters are not-intended to have their retention means inflated until the-inflatable means is within a body cavity. Nevertheless, urinary catheters are at times improperly inserted so'that inflation of the retention means is initiated while the latter is still within urethra. One of the recognized problems associated with partial inflation of retention means within arestricted body-channel whether the partial inflation beintentional or inadvertent is that theforce exerted by the inflation means, if excessive, may cause-trauma or even rupture of the channel walls.

An object of this invention is a tube with an expandable retention means which will expand fully or until itsexpansion is impeded by a resistance of a preselected amount.

, Another object of the invention is a urinary catheter with inflatable retention means which if improperly positioned with the retention means still in theurethra cannot inflate sufficiently to damage the latter.

Another object of the invention 'is to provide a urinary catheter withinflatable retention means which will produce a visual signal as an indication of improper positioning when inflation of the retention means is'attempted.

Other objects of the invention will be apparent from an inspection of the drawings and specification.

Referring now to the drawings: 1

FIG. I is a schematic representation showing a typical'insertion tube of the invention properly positioned with its inflatable retention means inflated within a body cavity and the signal means unactivated.

FIG. 2 isa schematic representation of the insertion tube of FIG. 1 improperly positioned and with its signal means actuated, indicating improper positioning. I

, FIG. 3 is an enlarged portion of a typical insertion tube of the inflatable retention typeshowing typical relative inflatable surface areas of the signal means and the retention means,

when both are of Similar-thicknesses of materialshaving similarelastic moduli.

FIG. 4 is another typical embodiment of the invention .wherein the, inflatable signal means is in the form of a thin Ion-- gitudinally extending edge-sealed patch. v

' FIG. 5 is anenlarged portion of another typical insertion tube of the inflatable retentio'ntype wherein the signal means is in the form of a relatively wide closed-edge.curvilinear patch.

elastic material connected by an inflation lumen or channel. The tube with one of the inflatable portions, the retention means, is intended to be inserted within the body and to be inflated at a lower pressurethan the other inflatable portions, the signal means. Thus, when the retention means meets with resistance, the pressure required to inflate it further rises above the pressure at which the signal means inflates. The signal means portion is caused to inflate at slightly higher pressures than the retention means be proper selection of shape and dimensions or by slightly increasing the thickness of the elastic material comprising this portion. The objects of the invention are also attained when noninflatable signal means actuated by fluid from the inflation lumen relieves the fluid pressure when it rises above that desired or visually indicates that the pressure should be relieved.

Likewise, the objects of the invention may be attained with expandableretention means when restrictions of expansion activates signal means mechanically.

Referring once more to the drawings; In FIG. 1, a typical insertion tube of the invention in the format a catheterll'l is shown schematically inserted into a body cavity such as the bladder 11, with the catheter tip 20, the drainage opening 21, and the inflated retention means 13 inside the bladder. A portion of the catheter lies within the urethra 12, but the inflatable signal means 14, the catheter bell 24, and the inflation branch or arm 25 are outside the body. An inflation lumen 16 in-the inflation branch 25 is continuous intothe catheter main arm 26 and connects to the inflated retention means 13 through the hole 17 and to the signal means 14 through the hole 18 in the main arm 26 of the catheter. A plug 15 which acts as a combination filling plug and stopper closes the lumen 16 in theinflation arm. The main arm 26 also contains a drainage lumen 19 which extends from the bell 24 to the drainage opening 21.

FIG. 2 shows the catheter of FIG. I improperly inserted so that the inflatable retention means 13 is still inside the urethra 12. This position, because "of the urethral wall resistance,

requires higher pressure to inflate the retention means. The

preferred form may prevent further increase of pressure thus preventing trauma. The inflating fluid may then be drawn from the catheter by inserting a hypodermic syringe needle in theusual manner for normally inflating and deflating a retentioncatheter, or the retention means may be further inserted FIG. 6 illustrates still another typical insertion tube of theinvention wherein an inflatable signal sleeve is substantially similar to the inflatable'sleeveretention means but is formed of thickerelastomer.

FIG. 7 illustrates another typical insertion tube of the'invention wherein the retention means is intended to be partially in-. flated in a body channel.

FIG. 8 illustrates a typical insertion tube of the invention in which an inflatable signal means is carried both on a side branch projecting from the main insertion tube and on the main insertion tube.

FIG. 9 illustrates another typical insertion tube of the invention in which the signal means is an ejectab'le plug.

FIG. 10 illustrates still another typical insertion tube in which liquid under pressure is used to activate the inflatable retention means and a rnicroporous body weeps or 'wets through when its preselected hydrostatic properties are overcome by liquid pressure thus constituting signal means.

FIG. II also illustrates atypical insertion tube of the invention in which a valve opens against a predetermined resilient resistance thus providing a fluid pressure relieving port, the

venting of the fluid constituting signal means.

beyond the channel and into the proper body cavity. Manual depression of the signal means will then inflate the retention means. In FIG. 2, an inflated reservoir 22 and a clamp 23 are shown constructively. With. this typecatheter, the reservoir is preinflated, its pressure being retained by the clamp. On release of the clamp. the elastic modulus of the reservoir in deflating provides'fluid pressure sufficient to inflate the retention'rneans if unimpeded or, as in this invention, if the retention means is impeded to inflate the signal means. With this type catheter the fluid may be removed with a hollow needle and syringe through the plug 15 in the usual fashion.

In FIG. 3, only a portion 30 of an inflatably retained insertion tube 31 is shown. The tube has a main lumen 34 and a small lumen 35 which normally is used to transmit the fluid for inflating the retention sleeve 32 and the signal sleeve 33. It is to be noted that although the sleeve 32 and the sleeve 33 have inflatable walls of substantially thesame thickness and are inflated by fluid from the same lumen through similar respective holes 36 and 37,the sleeve 32,.because of its greater length,

will inflate at a lower fluid pressure than the sleeve 33. Thus flated. However, when the retention sleeve must expand a body channel in order to inflate, a higher pressure must be used. The signal sleeve is thus selected to inflate at a higher pressure by making it correspondingly shorter in this particular embodiment. Thus, inflation of the signal indicates visually that the retention means is in contact with the channel wall at a preselected pressure. Likewise, when the retention means is intended to be retained in a body cavity, the inflated signal provides a visual warning that the retention means is improperly placed.

In FIG. 4, the portion 40 of the insertion tube 41 illustrates a typical inflatable retention means 42 and an inflatable signal means in the form of a thin longitudinally extending, edgesealed patch 43 joined by an inflation lumen 45 which opens into both the retention means sleeve and the signal means patch through the respective openings 46 and 47. The tube 41 also carries the main lumen 44. It is obvious that the location, shape and disposition of the external signal means is not eritical. For instance, it may be of various shapes disposed in one or more areas extending circumferentially, spirally or otherwise about the tube at any location exterior of the animal body and connecting to the inflation lumen.

In FIG. 5, the illustrated portion 50 of the insertion tube 51 which is generally similar to that illustrated in FIG. 4 contains a main lumen 54 and a lumen for inflation 55, The latter extends between the inflatable retention sleeve and a curvilinear inflatable-signal patch 53. An opening 52 from lumen 55 permits fluid to enter inflatable signal patch 53 in amounts suffcient to at least appreciably inflate it wherever the proper pressure is reached. 1

In FIG. 6 is illustrated a portion of an insertion tube 61 which has a main lumen 64 and a lumen for inflation 65. The lumen 65 connects the inflatable retention sleeve 62 with the inflatable signal sleeve 63 by means of the respective ports 66 and 67. The cross sections demonstrate that where the two sleeves are otherwise similar, the retention sleeve should have a thinner wall 68 than the signal sleeve wall 69. This embodiment is not preferred, however, because the thickness of latex deposited by one or more dips is difficult to control and more accurate results may normally be obtained in production by varying the length of the signal sleeve, or where a patch is utilized, the size and shape of'the inflatable signal patch. The formation of catheters and other tubes by latex dipping is a well known art. It is also well known to coat a stripe, band, patch, or other area on a partially completed catheter with a coating of a material such as bentonite surrounding a clay-filled hole. The bentonite coated area adheres only lightly if at all to further latex dip coats and causes a skin to be formed covering the hole through to the inflation lumen. This skin, when the underlying coating material and the hole plug is washed away, is inflatable because it is deposited on and unifies with latex bordering the bentonite coated area.

in FIG. 7 is illustrated a portion 70 ofa tube 71 which contains a main lumen 74 and an inflation lumen 75. The retention sleeve 72 is intended to inflate against the walls ofa body channel 78. The inflation lumen 75 connects the inflatable sleeve 72 to the inflatable signal 73 by means of ports 76 and 77, respectively. The amount of pressure which the retention sleeve may exert on the body channel 78 will vary with the particular type of channel and the maximum pressure which the channel will withstand without damage. The maximum obviously should not be approached under ordinary conditions and the sleeve 73 should be made sufficiently long that it inflates at pressures short of this maximum.

FIG. 8 illustrates the external portion 80 of an insertion tube 81 which in the embodiment illustrated is similar generally to that illustrated more completely in FIGS. 1 and 2 but broken off at the bell 82.. The tube 81 contains a main lumen 88 and an inflation lumen 36 which extends from the main arm 1 into the side branch 83. The insertion tube illustrated contains two signal devices which are intended to inflate either at the same or at different pressures. Such a tube may beuseful where the reservoir 89 contains more liquid than one inflatable signal means could hold. Where the pressures inflating the two are different, the device would indicate that the pressures were in a definite range when one inflates and the other does not. At any rate, although two or more inflatable signal means may be placed on one branch of the insertion tube, in the embodiment shown, the signal means 91 which has an inflation opening 92 into the inflation lumen 86 is on the main arm 31. Another inflatable signal means 84 which is shown construetively inflated is on the side branch 83 and also has an opening 87 into the inflation lumen 86. A filling and stopper plug closes the inflation lumen. Obviously this may be replaced by valve means. A self-inflating type catheter portion is shown constructively. The reservoir 89 is shown inflated with the clamp retaining the fluid in the latter.

In FIG. 9, a portion of an insertion tube 101 is shown with a main lumen 104 and an inflation lumen 105. An inflata ble retention means 102 connects to the lumen 105 by means of the opening 186. Also opening into the inflation lumen is a side branch 108 which has a rigid sleeve 107 retained by the stretched walls of the side branch. A plug 103 fits into the sleeve 107 to be ejected when the fluid pressure reaches a preselected amount, thus providing signal means and relieving the pressure In FIG. 10, a portion 110 of an insertion tube 111 is shown with a main lumen 114 and an inflation lumen 115. An inflatable retention means 112 connects to the inflation lumen 115 by means of the opening 116. A side arm 113 also opens into the inflation lumen 115. A microporous body or a filter 117, which is incapable of retaining the hydrostatic pressure beyond a selected point, wets through or weeps providing a signal that the selected pressure has been exceeded.

In FIG. 11 a portion of an insertion tube 121 is shown with a main lumen 124 and an inflation lumen 125. An inflatable retention sleeve 122 connects with the inflation lumen through the opening 126. A side branch 127 also connects into the inflation lumen. A valve 129 is retained in seated position on the inlet opening of the chamber 132 by a spring 131. The walls of the side branch are stretched to retain the chamber 132 in place. A vented plug 130 positions the spring under compression. When the fluid pressure rises above the selected pressure the spring is compresses still further and the valve 129 lifts off its seat, the fluid escaping around its circumference and out through the vent 128 thus acting as a signal and relieving the pressure.

lclaim:

1. In an inflatable retention catheter comprising a length of flexible tubing having a proximal end and a distal end for insertion into an animal body cavity, said catheter having a main fluid path lumen and a separate inflation lumen within said tubing terminating in an inflatable retention member proximate the distal end inflatable at a given fluid pressure, the improvement comprising in combination therewith a signal member positioned proximate the proximal end of said catheter, said signal member also communicating with the inflation lumen, said signal member comprising means adapted to be activated only at a fluid pressure greater than that pres sure normally required to inflate the retention member whereby when inflation of the retention member is impeded by body tissue, a higher inflation pressure is created thereby activating said means, preventing further inflation of the retention member and providing an indication of such impediment.

2. A catheter in accordance with claim 1 wherein the signal member comprises a sleeve encircling said flexible tubing hav- 1 ing opposed edges sealed to the tubing and communicating 4. A catheter in accordance with claim 1 wherein the signal bifurcated branch havingthe inflation lumen includes an orifice communicating with said inflation lumen and the signal member comprises a plug sealingly fitted within said orifice,

municating with the inflation lumen, said plug being ejectable from the'orifice at a fluid pressure greater than that pressure normally required to inflate theretention member.

5. A catheter in accordance with claim 1 wherein the signal member comprises a valve adapted to open at a fluid pressure greater than v that pressure normally required to inflate the retention member, said valve opening out of the inflation lumen to allow fluid to escape from said inflation lumen when said valve is open.

6. A catheter in accordance with claim 1 wherein a portion of the catheter tubing includes an orifice communicating with the inflation lumen and the signal member comprises a microporous body sealingly seated within said orifice, said body being capable of wetting through and weeping at a fluid pressure greater than that pressure normally required to inflate the retention member. v

7, A catheter in accordance with claim 1 having a first signal member and a second signalmember, each of said signal members being positioned proximate the proximal end of said catheter, eachof said signalmembers communicating with the inflation lumen and being adapted to be activated at a fluid pressure greater than that pressure normally required to inflate the retention member. v

8. A catheter in accordance with claim 7 wherein both of the signal members are adapted to be activated at the same pressure, said fluid pressure being greater than that pressure normally required to inflate the retention member.

9. A catheter in accordance with claim 7 wherein the first signal member is adapted to be activated at a fluid pressure.

greater than that pressuren'ormally required to inflate the retention member, and the second signal member is adapted to be activated at a fluid'pressure greater than that pressure for activating the first signal member, such that a definite range of fluid pressure may be established upon activation of said signal members.

. 10. A catheter in accordance with claim 1 wherein the proximal end of the catheter is bifurcated with the inflation lumen extending into one branch of the bifurcated tube and the main fluid path lumen extending into the other branch thereof, and the signal member is positioned on on the distal side of the point of bifurcation of the catheter, said signal member being in communication with the inflation lumen.

11. A catheter in accordance with claim 10 wherein the signal member comprises a sleeve encircling said flexible tubing having opposed edges sealingly engaged with said tubing and communicating with the inflation lumen through an orifice in the tubing, said sleeve being adapted to inflate at a pressure greater than that pressure normally required to inflate the retention member.

12. A catheter in accordance with claim 1 wherein the proximal end of the catheter is bifurcated with the inflation lumen extending into one branchofthe bifurcated tube and the main fluid path lumen extending into the other branch thereof, and the signal member is positioned on the branch of said bifurcated tube having the inflation lumen therein, with said signal member being in communication with the inflation lumen.

13. Acatheter in accordance with claim 12 wherein the signal member comprises a sleeve encircling the branch of said bifurcated tube having'the inflation lumen therein, said sleeve having opposed edges sealed to the tubing and communicating with the inflation lumen through an orifice in the tubing, said sleeve being adapted to inflate at a pressure greater than that pressure normally required to inflate the retention member.

14. A catheter in accordance with claim 12 wherein the said plug being ejectable at a fluid pressure greater than that pressure normally required to inflate the retention member.

15 A catheter m accordance Wlth claim 12 wherein the bifurcated branch having the inflation lumen includes an orifice communicating withthe inflation lumen and the signal member comprises a microporous body sealingly seated within said orifice, said body being capable of wetting through and weeping at a fluid pressure greater than that pressure normally required to inflate the retention member.

16. A catheter in accordance with claim 12 wherein the signal member is a valve positioned on that branch of the bifurcated tube having the inflation lumen, said valve being adapted to open at a fluid pressure greater than that normally required to inflate the retention member, said valve opening out of the inflation lumen to allow fluid to escape from said inflation lumen when said valve is open.

17.. A catheter in accordance with claim 12 wherein the signal member comprises an, edge-sealed patch of elastic materialoverlying an orifice in the tubing of that branch of said bifurcated tube having the inflation lumen therein, said orifice communicating with said inflation lumen, said sealed patch being adapted to inflate at a fluid pressure greater than that pressure normally required to inflate the retention member. a g

18. A catheter in accordance with claim 12 wherein a first signal member is positionedon the flexible tubing along the proximal end thereof, and a second signal member is positioned on the branch of the bifurcated tube having the inflation lumen,-each of said signal members communicating with the inflation lumen and each being adapted to be activated at a fluid pressure greater than that pressure normally required tention member, and the second signal member is adapted to be activated at a fluid pressure greater than that pressure for activating the first signal member such that a definite range of fluid pressure may be established upon activation of said signal members.

21. A catheter in accordance with claim 12 having a first signal member and a second signal member, each of said signalmembersbeing positioned on the branch of the bifurcated tube having the inflation lumen, each of said signal members communicating with-the inflation lumen and each being adapted to be activated at a fluid pressure greater than that pressure normally required to inflate the retention member.

22. A catheter in accordance with claim 21 wherein both of the signal members are adapted to be activated at the same signal members. 

